/*
This file is part of GNUnet
Copyright (C) 2013, 2014, 2016 GNUnet e.V.
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
* @file gns/plugin_gnsrecord_gns.c
* @brief gnsrecord plugin to provide the API for fundamental GNS records
* This includes the VPN record because GNS resolution
* is expected to understand VPN records and (if needed)
* map the result to A/AAAA.
* @author Christian Grothoff
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_gnsrecord_lib.h"
#include "gnunet_dnsparser_lib.h"
#include "gnunet_gnsrecord_plugin.h"
#include
/**
* Convert the 'value' of a record to a string.
*
* @param cls closure, unused
* @param type type of the record
* @param data value in binary encoding
* @param data_size number of bytes in @a data
* @return NULL on error, otherwise human-readable representation of the value
*/
static char *
gns_value_to_string (void *cls,
uint32_t type,
const void *data,
size_t data_size)
{
const char *cdata;
switch (type)
{
case GNUNET_GNSRECORD_TYPE_PKEY:
if (data_size != sizeof(struct GNUNET_CRYPTO_EcdsaPublicKey))
return NULL;
return GNUNET_CRYPTO_ecdsa_public_key_to_string (data);
case GNUNET_GNSRECORD_TYPE_NICK:
return GNUNET_strndup (data, data_size);
case GNUNET_GNSRECORD_TYPE_LEHO:
return GNUNET_strndup (data, data_size);
case GNUNET_GNSRECORD_TYPE_GNS2DNS: {
char *ns;
char *ip;
size_t off;
char *nstr;
off = 0;
ns = GNUNET_DNSPARSER_parse_name (data, data_size, &off);
ip = GNUNET_DNSPARSER_parse_name (data, data_size, &off);
if ((NULL == ns) || (NULL == ip) || (off != data_size))
{
GNUNET_break_op (0);
GNUNET_free_non_null (ns);
GNUNET_free_non_null (ip);
return NULL;
}
GNUNET_asprintf (&nstr, "%s@%s", ns, ip);
GNUNET_free_non_null (ns);
GNUNET_free_non_null (ip);
return nstr;
}
case GNUNET_GNSRECORD_TYPE_VPN: {
struct GNUNET_TUN_GnsVpnRecord vpn;
char *vpn_str;
cdata = data;
if ((data_size <= sizeof(vpn)) || ('\0' != cdata[data_size - 1]))
return NULL; /* malformed */
/* need to memcpy for alignment */
GNUNET_memcpy (&vpn, data, sizeof(vpn));
GNUNET_asprintf (&vpn_str,
"%u %s %s",
(unsigned int) ntohs (vpn.proto),
(const char *) GNUNET_i2s_full (&vpn.peer),
(const char *) &cdata[sizeof(vpn)]);
return vpn_str;
}
case GNUNET_GNSRECORD_TYPE_BOX: {
struct GNUNET_GNSRECORD_BoxRecord box;
uint32_t rt;
char *box_str;
char *ival;
cdata = data;
if (data_size < sizeof(struct GNUNET_GNSRECORD_BoxRecord))
return NULL; /* malformed */
GNUNET_memcpy (&box, data, sizeof(box));
rt = ntohl (box.record_type);
ival = GNUNET_GNSRECORD_value_to_string (rt,
&cdata[sizeof(box)],
data_size - sizeof(box));
if (NULL == ival)
return NULL; /* malformed */
GNUNET_asprintf (&box_str,
"%u %u %u %s",
(unsigned int) ntohs (box.protocol),
(unsigned int) ntohs (box.service),
(unsigned int) rt,
ival);
GNUNET_free (ival);
return box_str;
}
default:
return NULL;
}
}
/**
* Convert human-readable version of a 'value' of a record to the binary
* representation.
*
* @param cls closure, unused
* @param type type of the record
* @param s human-readable string
* @param data set to value in binary encoding (will be allocated)
* @param data_size set to number of bytes in @a data
* @return #GNUNET_OK on success
*/
static int
gns_string_to_value (void *cls,
uint32_t type,
const char *s,
void **data,
size_t *data_size)
{
struct GNUNET_CRYPTO_EcdsaPublicKey pkey;
if (NULL == s)
return GNUNET_SYSERR;
switch (type)
{
case GNUNET_GNSRECORD_TYPE_PKEY:
if (GNUNET_OK !=
GNUNET_CRYPTO_ecdsa_public_key_from_string (s, strlen (s), &pkey))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_ ("Unable to parse PKEY record `%s'\n"),
s);
return GNUNET_SYSERR;
}
*data = GNUNET_new (struct GNUNET_CRYPTO_EcdsaPublicKey);
GNUNET_memcpy (*data, &pkey, sizeof(pkey));
*data_size = sizeof(struct GNUNET_CRYPTO_EcdsaPublicKey);
return GNUNET_OK;
case GNUNET_GNSRECORD_TYPE_NICK:
*data = GNUNET_strdup (s);
*data_size = strlen (s);
return GNUNET_OK;
case GNUNET_GNSRECORD_TYPE_LEHO:
*data = GNUNET_strdup (s);
*data_size = strlen (s);
return GNUNET_OK;
case GNUNET_GNSRECORD_TYPE_GNS2DNS: {
char nsbuf[514];
char *cpy;
char *at;
size_t off;
cpy = GNUNET_strdup (s);
at = strchr (cpy, '@');
if (NULL == at)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_ ("Unable to parse GNS2DNS record `%s'\n"),
s);
GNUNET_free (cpy);
return GNUNET_SYSERR;
}
*at = '\0';
at++;
off = 0;
if ((GNUNET_OK != GNUNET_DNSPARSER_builder_add_name (nsbuf,
sizeof(nsbuf),
&off,
cpy)) ||
(GNUNET_OK !=
GNUNET_DNSPARSER_builder_add_name (nsbuf, sizeof(nsbuf), &off, at)))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_ ("Failed to serialize GNS2DNS record with value `%s'\n"),
s);
GNUNET_free (cpy);
return GNUNET_SYSERR;
}
GNUNET_free (cpy);
*data_size = off;
*data = GNUNET_malloc (off);
GNUNET_memcpy (*data, nsbuf, off);
return GNUNET_OK;
}
case GNUNET_GNSRECORD_TYPE_VPN: {
struct GNUNET_TUN_GnsVpnRecord *vpn;
char s_peer[103 + 1];
char s_serv[253 + 1];
unsigned int proto;
if (3 != sscanf (s, "%u %103s %253s", &proto, s_peer, s_serv))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_ ("Unable to parse VPN record string `%s'\n"),
s);
return GNUNET_SYSERR;
}
*data_size = sizeof(struct GNUNET_TUN_GnsVpnRecord) + strlen (s_serv) + 1;
*data = vpn = GNUNET_malloc (*data_size);
if (GNUNET_OK !=
GNUNET_CRYPTO_eddsa_public_key_from_string ((char *) s_peer,
strlen (s_peer),
&vpn->peer.public_key))
{
GNUNET_free (vpn);
*data_size = 0;
return GNUNET_SYSERR;
}
vpn->proto = htons ((uint16_t) proto);
strcpy ((char *) &vpn[1], s_serv);
return GNUNET_OK;
}
case GNUNET_GNSRECORD_TYPE_BOX: {
struct GNUNET_GNSRECORD_BoxRecord *box;
size_t rest;
unsigned int protocol;
unsigned int service;
unsigned int record_type;
void *bval;
size_t bval_size;
if (3 != sscanf (s, "%u %u %u ", &protocol, &service, &record_type))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_ ("Unable to parse BOX record string `%s'\n"),
s);
return GNUNET_SYSERR;
}
rest = snprintf (NULL, 0, "%u %u %u ", protocol, service, record_type);
if (GNUNET_OK != GNUNET_GNSRECORD_string_to_value (record_type,
&s[rest],
&bval,
&bval_size))
return GNUNET_SYSERR;
*data_size = sizeof(struct GNUNET_GNSRECORD_BoxRecord) + bval_size;
*data = box = GNUNET_malloc (*data_size);
box->protocol = htons (protocol);
box->service = htons (service);
box->record_type = htonl (record_type);
GNUNET_memcpy (&box[1], bval, bval_size);
GNUNET_free (bval);
return GNUNET_OK;
}
default:
return GNUNET_SYSERR;
}
}
/**
* Mapping of record type numbers to human-readable
* record type names.
*/
static struct
{
const char *name;
uint32_t number;
} gns_name_map[] = { { "PKEY", GNUNET_GNSRECORD_TYPE_PKEY },
{ "NICK", GNUNET_GNSRECORD_TYPE_NICK },
{ "LEHO", GNUNET_GNSRECORD_TYPE_LEHO },
{ "VPN", GNUNET_GNSRECORD_TYPE_VPN },
{ "GNS2DNS", GNUNET_GNSRECORD_TYPE_GNS2DNS },
{ "BOX", GNUNET_GNSRECORD_TYPE_BOX },
{ NULL, UINT32_MAX } };
/**
* Convert a type name (i.e. "AAAA") to the corresponding number.
*
* @param cls closure, unused
* @param gns_typename name to convert
* @return corresponding number, UINT32_MAX on error
*/
static uint32_t
gns_typename_to_number (void *cls, const char *gns_typename)
{
unsigned int i;
i = 0;
while ((NULL != gns_name_map[i].name) &&
(0 != strcasecmp (gns_typename, gns_name_map[i].name)))
i++;
return gns_name_map[i].number;
}
/**
* Convert a type number (i.e. 1) to the corresponding type string (i.e. "A")
*
* @param cls closure, unused
* @param type number of a type to convert
* @return corresponding typestring, NULL on error
*/
static const char *
gns_number_to_typename (void *cls, uint32_t type)
{
unsigned int i;
i = 0;
while ((NULL != gns_name_map[i].name) && (type != gns_name_map[i].number))
i++;
return gns_name_map[i].name;
}
/**
* Entry point for the plugin.
*
* @param cls NULL
* @return the exported block API
*/
void *
libgnunet_plugin_gnsrecord_gns_init (void *cls)
{
struct GNUNET_GNSRECORD_PluginFunctions *api;
api = GNUNET_new (struct GNUNET_GNSRECORD_PluginFunctions);
api->value_to_string = &gns_value_to_string;
api->string_to_value = &gns_string_to_value;
api->typename_to_number = &gns_typename_to_number;
api->number_to_typename = &gns_number_to_typename;
return api;
}
/**
* Exit point from the plugin.
*
* @param cls the return value from #libgnunet_plugin_block_test_init()
* @return NULL
*/
void *
libgnunet_plugin_gnsrecord_gns_done (void *cls)
{
struct GNUNET_GNSRECORD_PluginFunctions *api = cls;
GNUNET_free (api);
return NULL;
}
/* end of plugin_gnsrecord_gns.c */